Polymers made from 1-aziridinyl phosphine oxides and sulfides and flame resistant organic textiles



United States Patent 2,901,444 POLYMERS FROM l-AZIRTDINYIJ PHDS' PHINE AND SUEFIDES FLAME RESISTANT ORGANIC TEXTILES Leon H. Chance, George: L. Drake, Jr., and Wilson A. Reeves, New Orleans, La., assignors to the United States: of America as represented by the Secretary of Agriculture NoDrawing. Application-June '5, 1956 Serial-No.,589,560'

, 4 Claims. (.Cl.-260--2)' (Granted under Title 35, US. Coded-I952), sec.- 266) A non-exclusive; irrevocable; royalty freelicense in. the

invention herein. describecfi. throughout-the. world for all attached to pentavalent phosphorus),

We have discovered that compounds which contain at phorus halide. The preparation of tris( l-aziridinyDphosphine oxide, [(CH N] PO, has been described by Bestian and coworkers [Bestian et.al.,v Ann. 566, 210.444 (195.0.) 1.

Polymers. provided by this invention can be produced in acidic, neutral, and alkaline conditions. They can be produced in the form of liquids or solids and can be molded by the conventional techniques of molding thermosetting resins but are more easily produced in the form of: These polymers are valuable. materials. for use in. production of: molded synthetic. articles, such as buttons, electrical insulators and. the like; synthetic coatings such as protective coatings having reduced flammability; paper treating resins; textile resins; and the like having reduced flammability.

The polymers provided bythisinvention are preferably prepared by gently heating an aqueous solution of the azi'ridinyl phosphine oxide or sulfide in aboutneutral or slightly alkaline conditions until polymerization occurs.

The combustibility of organic fibrous materials can be reduced in accordance with this invention by impregnating the fibrous materials'with an aqueous solution, or uniform suspension or dispersion, of the monomeric compounds, or. the partially polymerized. monomers formed by reacting, the monomeric compounds until partial polymerization occurs and curing the impregnated materials at the temperatures conventionally used for curing fibrous orleast two l -aziridinylgroups attached' to pentava-lent phos- L phorus atoms polymerize when heated in the presence. of trace quantities of water. The resulting polymers contain the characteristic reocurring connecting structure P-l 1'O Hr C HrI I -P wherein the phosphorus atoms are pentavalent.

Such polymers can be produced in the form' of solid synthetic resins. They can be: deposited on the surfaces and/or in the interstices of hydrophilic fibrous organic materials, i.e., organic materials which, absorb or adsorb water. When such resins are deposited, they reduce. the

combustibility of liydropliilic fibrous organicmaterials or a dialkyl amine group such as and where Z is oxygen or sulfur. The aziridinyl compounds can be prepared by substantially any of the known processes for producing such compounds. In general, they are prepared by reacting ethylenimine or alkyl substituted ethylenimines with the corresponding phosganic materials.

Surface. active agents, water repellents, and other textile treating agents may be incorporated into the aqueous or emulsion treating media to modify the treated textiles. Surface active softening agents improve tear strength of cotton and rayon fabrics.

The process of this invention can be used to reduce the combustibility of substantially any hydrophilic fibrous material such as cotton, rayon such as viscose rayon, ramie, jute, wool, paper, cardboard and the like materials which can be impregnated with a liquid and dried or cured. When the resins are applied to cellulosic materials, some. cross linking occurs with the cellulosic hydroxyl groups. In the case. of cotton textiles the cross linking causes a loss in tear and tensile strength. Where a. textile is being impregnated, it is of advantage to remove excess impregnating liquor by passing the textile through squeeze rolls prior to drying or curing the impregnated textile. It is also advantageous to drythe textile at about 70 to C. before it is cured at a temperature of from about 100 to 170 C.

The degree of flame resistance imparted to a textile by these phosphorus and nitrogen containing resins can be varied from a low degree to a very high degree by varying the amount of polymer put in the textile.

Some advantages of flameproofing textiles in accordance with this invention are: textiles treated by this process are flame resistant, glow resistant, shrink resistant, and rot and mildew resistant; the effects of the treatment are permanent, and resistant to laundering, dry cleaning, and boiling alkali solutions; treated textiles are made highly flame resistant with relatively small amounts of the phosphorus and nitrogen containing polymers.

The following examples illustrate this invention. The flame test used in evaluating the fabrics .in this invention was the standard vertical flame test as specified in Federal Specification CCC-T-191b. The test for permanency of the flame resistant agent was that of boiling for 3 hours in an aqueous solution containing 0.5% laundry soap and 0.2% sodium carbonate. In the examples, the term part refers to parts by weight.

Example 1 Six parts of tris(l-aziridinyl)phosphine oxide were heated at C. for 40 minutes. A clear hard polymer A solution consisting of one part tris(l-aziridinyl) phosphine oxide, one part water, and 0.1 part triethanolamine (as a basic catalyst) was heated on a steam cone for 30 minutes, and then at 140 C. for 10 minutes. A clear hard polymer containing nitrogen and phosphorus was formed which was insoluble in boiling Water, benzene, acetone, and tetrachloroethylene. It adhered to glass very well.

A polymer was formed in a similar manner using 0.2 part of 18% hydrochloric acid as a catalyst instead of a base. The water was evaporated in a vacuum and the polymer heated for one hour on a steam cone and cured for 30 minutes at 110 C.

Example 3 An aqueous solution with a pH of 9.4 was prepared containing 25% tris(1-aziridinyl)phosphine oxide, 4% triethanolamine, and 2% cationic softener. The solution was applied to 8.2 02. cotton twill in a padder to give 65% wet pick-up. The fabric was dried for 3 minutes at 85 C. and then cut into four pieces and each portion was heated for 5 minutes at a given temperature. After curing, the samples were washed in running hot water for 30 1 BEL=Burnecl entire length of -inch sample.

From the table above it is seen that the percent addon increases with the curing temperature. The samples cured within the range of 140l50 C. showed excellent Example 4 An aqueous solution with a pH of 6.4 was prepared containing 25 tris(l-aziridinyDphosphine oxide, 2.0% cationic softener, 3.0% acetic acid, 4.1% sodium acetate, and 66% water. This solution was used to treat 8 oz. cotton twill fabric as described in Example 3. Samples of the treated cotton twill that were cured at 150 C. contained 12% resin and had a char length of 3.8 inches.

Example 5 A sample of 8.2 oz. cotton twill was padded through a. solution containing 15% tris(1-aziridinyl)phosphine sulfied, 15% tris(1-aziridiny1)phosphine oxide, 4% triethanolamine and 66% H O. The fabric was given two dips and two nips using a very tight squeeze roll pressure. The sample was dried for 4 minutes at -90 C. and cured for 5 minutes at C. using a forced draft oven for both the dry and cure. The fabric was washed and dried. Resin add-on of 11.8% was obtained.

The treated fabric was flame resistant and glow resistant.

We claim:

1. A process for producing a flame resistant polymer which comprises heating in an aqueous alkaline medium, a material selected from the group consisting of tris(laziridinyl)phosphine oxide, tris(l-aziridinyDphosphine sulfide, and mixtures thereof until polymerization takes place.

2. The process of claim 1 wherein the material heated is tris(1-aziridinyl)phosphine oxide.

3. The process of claim 1 wherein the material heated is tris(1-aziridinyl)phosphine sulfide.

4. The process of claim 1 wherein the material heated is a mixture of tris(1-aziridinyl)phosphine oxide and tris(1-aziridinyl)phosphine sulfide.

References Cited in the file of this patent UNITED STATES PATENTS 2,582,613 Wohnsiedler et al Jan. 15, 1952 2,606,901 Parker Aug. 12, 1952 2,654,738 Lecher Oct. 6, 1953 2,660,543 Walter et al. Nov. 26, 1953 2,666,750 Dickey et al. Ian. 19, 1954 2,672,459 Kuh Mar. 16, 1954 2,682,521 Coover June 24, 1954 2,772,188 7 Reeves et a1 Nov. 27, 1956 FOREIGN PATENTS 854,651 Germany Nov. 6, 1952 863,055 Germany Jan. 15, 1953 888,853 Germany Sept. 7, 1953 

1. A PROCESS FOR PRODUCING A FLAME RESISTANT POLYMER WHICH COMPRISES HEATING IN AN AQUEOUS ALKALINE MEDIUM, A MATERIAL SELECTED FROM THE GROUP CONSISTING OF TRIS(1AZIRIDINYL) PHOSPHINE OXIDE, TRIS(1-AZIRIDINYL) PHOSPHINE SULFIDE, AND MIXTURES THEREOF UNTIL POLYMERIZATION TAKES PLACE. 